Automatic control device



C. FV. JOHNSON. Aummlw ummm DEVICE. APPLICATION FILEU MAR. l2. lBlB.

i l 312,253. Patented Aug. 5, 1919. y 3 SHEETS-SHEET 1.

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C. F. IOHNSON.

AUTOMATIC CONTROL DEVICE.

APPLlcATioN FILED MAR. 11.1918.

SHEETS-SHEET 2f C. F. JOHNSON.'

AUTOMANC Comm APPLICATION FlLEU MAR 12. 1918.

DEVICE Pamuted A1102. 5, 19H).

3 SHEETSf-SHEET 3.

@Home L45.

and serves to move-a leak tube or vent member 6, which is loosely"`andslidablymounted in an exteriorly-threaded nipple 6a, screwed intol"aninternally threaded neck .2a of the front plate 2. Nipple 6a has ahead 6". at its outer end, which may 'be of polygonal form, milled, orotherwise adapted for ready turning for purposes of longitudinaladjustment relatively to the front plate 2. Back of the front plate 2,or within the chamber vot which said plate forms the outer wall,

screw thread to receive an adjustable stop nut 7, which limits theinward movement of said leak tu'be 6, the outward movement of which. islimited and determined by the flange 6c and nipple6", against the innerend of which said flange ab-uts, when the. leak tube moves outward. f

It will be observed hatthe adjustable stop or nut 7 here takes the placeof the integral stop collar 7 of Patent-No. 1,162,170, and

' vthat nipple 6 providesfanv adjustable stop or abutment for flange 6,in place of the fixed abutment of said patent. Instead of a fixed rangeof movement of one or two onethousandthsiof an inch contemplated andusually provided under the former construction,.I am enabled to giveamuch wider range of movement tothe leak tube 6,' and lto vary the playat will Within the extreme limits of such 'wider range.

The diaphragm 3 maybe of thin resilient metal, but is preferably made ofquite flexible material,` as leather or rubberf'abric, to permitconsiderableplay or flexure. Its -olice is to urge the leak tube' 6inward,

Y but to allow it to move outward under moderate vpressure in thechamber 9, to the left of diaphragm 3.

-The chamber 10 tothe right ofsaid dia.- phragrn 3, is open to theatmosphere by rea- I son of a loose fit of the leak tube in the nipple6, so that the pressure in chamber 10 is practically constant, and hasno function 1 in the operation of the device.

Chamber 9 is separated from chamber 11 by the diaphragm 4., which isrelatively flexible, being made of any suitable material impervious toair, as leather, rubber fabric7 or the like.

Chamber 11 opens to the atmosphere through an exhaust port 12.

To the rear of chamber 11 is a chamber 22,

when not opposed by sucommon form.

and to the rear of chamber is a chamber 27,`said chambers 22 and 27being separated by a cross wall or partition 26, which carries aslideway 15 for the tubular stem of a valve 13, which in the positionindicated in Fig. 1, seals a port 16 formed in the cross wall orpartition 26. The tubular form of the stem of valve 13 provides alongitudinal exhaust port 14, through which chamber 27 and pipe 23 incommunication therewith may be vented to exhaust-chamber 1l, and thenceby port 12 to the atmosphere..

17 indicates a pipe which in use is placed in communication, with anaccumulator, reservoir, or source of fluid under pressure. Said pipecommunicates by, a reduced port or passage 19, regulated by a needlevalve 20 with chamber 9; and by another port or passage 18 with chamber22. When the supply port 16 is unsealed by valve 13, chamber 22communicates with chamber 27 and pipe 23, which latter connects with themot-or to be operated. This is commonly a dia )hragm motor actuating adamper, or a va ve controlling delivery of a heating or moisteningmedium, as steam or water. Figs. 1 and 4 show in outlinesuch a motor andvalve, in

The parts above described are so'arranged and adjusted that whendiaphragm 4 moves to the left it first seals the exhaust port 14, andthen moves the valve member 13 bodily rearward, thereby unsealing supplyport 16. Pressure of air or other fluid acting against;

therear or left face of diaphragm 5 constantly urges it'outward or tothe right, and when pressure in chamber 9 to the right of diaphragm 4falls, valve 13 will be moved by diaphragm 5 outward or to the right andcaused to seal supply port 16, after which pipe 23 and chamber 27 willbe vented to the vatmosphere by port 14, chamber 11, and

port 12.

Valve 13 and its co-acting parts Constitute merely a supply and exhaustvalve serving to-supply pressure fluid to and release it from asecondary motor of any suitable type, connected with pipe 23. As in thecase ol the structure of Patent No. 1,162,170, so in the presentinstance I may substitute t'or this valve 13 any suitable mechanismoperable by the diaphragm 4 or similar primary motor and adapted tocontrolthe operation of a secondary motor.

24 indicates a bimetallic thcrniostatic bar such as commonly employed inthermostatsv of the Johnson system. By reason of the differentco-eiiicients of expansion of the two metals or substances employed,such bar bends or flexes one way under rise of temperature, and in thereverse direction on fall of temperature. One end of such bar is heldfixedly iii place (after initial setting or adjustment), and the otherend or free temete' gy Y movable to and from and alternately serving 4toseal and unseal the minute leak port, permits of a sensitive control andclose regulation not obtainable bv most other constructions.' This, ishence the preferred form ot -thermostatio element and seal.

Vstood need not be described here.

Usual means may be provided tor initial adjustment of the supportnet thethermostatic element, but this being well under# llt will be observed byreference to Fig. 1 that with the parts in the positions there shown,the valve-pad -or face Jis held away from the'leaktube -6 bythebimetallicloar 2l. 1'lhe'needle valve20` is so adjusted as to restrictthe dow through port 19 to', a

i point less than the capacity of the leak tube 6, so that said leakltube may edectually ventthe chamber 9, and Vprevent any accumulation ofpressure therein while the leak tube is unsealed. From this it followsthat diaphragm 4f stands in its right-hand or forward position, andpermits a closing et supply port 16 and-a venting of pressure from pipe2 3 and its connected motor', as above explained.

llt will also be seen thatthe 4diaphragm 3, pressed inward by spring 6or bowed inward by reason of its own resilience, maintains the leak tube6 in itsinward Oriett-4 hand position whenv the parts are in therelations shown anddescribedl llt, now, in

- consequence ofthe change 4of temperature,

the bimetallic bar 24: moves valve face 25 toward leak'tube 6, thefollowing action takes place: rlhe retardation of How through the leaktube 6, which begins as the pad or valve-face 2 5 closely approaches theend ot said tube,rwill cause arise ot pressure in chamber 9, which,4acting upon dia-` thereby moving the leak tube and. causing its end topress firmly against the valve-face 25, thus sealing the leak-passagethrough said tube, such movement of the leak tube continuing until .itsflange 6 abuts against the inner end of nipple 6a. immediately thissealing takes place, pressure will rapidly rise in chamber 9, forcingdiaphragm 4lto phragm 3, will force thesame to the right 1the lett Vsoas to seal the port 14 and 'to ,move valve 1 3 from its seat around port16, thereby opening said port. Air will thereupon flow through pipe 17,Veb amber 22, port 16, and chamber 27 to the pipe 23, and thence to thedampenmotonor other place of nal use.

. Upon a subsequent and reverse change of temperature, a very slightmovement of valve-pad or :tace 25 away from leak tube f 6 will initiatea venting of chamber 9 suf icient to cause diaphragm 3 to move the leaktube 6 to the left to an extent limited and determined by the`adjustable stop-nut i' on the `outer portion of the leak tube cominginto contact with the outerend ot nipple 6a. Suchmovement, quicklyeffecting a wide separatlon of the nipple and the valve-faceor pad 25,insures a rapid dis-` charge from the chamber 9 and a quick movement ofdiaphragm 5 to the right, with consequent` closing oi" supply port 16 byvalve 13 and opening of exhaust port 1a, which in turn vents thedamper-'motor or other ultimate device, permitting it to move in areverse direction from that in which, it was previously actuated by theHuid pressure.

Fig. 2showsthe leak port mechanism oi Fig. 1 embodied in a unitstructure for applicationto control apparatus of any type adapted toreceive it.' ln this `the outer.

plate 2, diaphragm 3, leak tube 6, nipple 6a, and adjustable stop-nut 7are ot the same construction and arrangement as in Fig. 1, but chamber 9is formed as a special or detached shell 1a, provided with a threadednipple 1b to screw into a trame having thenremaining elements of Fig. 1,or their. equivalents.

ln Fig. 8 ll have illustrated the invention as applied to a type otthermostat in which the element having a relatively high co ellicient ofexpansion takes the term ot a tube 2da, and is arranged to eileet by.its longitudinal expansion and contraction, the sealing and unsealingof a leak tube 6 carried by a diaphragm 3, which is pressed backward orupward by a spring 6 as in the structure shown in Figs. 1 and 2. 'llhemain trame of the instrument, 1, is essentially as in Fig. 1 except thatthe portion containing the diaphragm chamber 9 is arranged in ahorizontal instead of a vertical position. rllhe supply pipe 17 with itsport 19, needle valve 20,`and sealing screw 21 are unchanged. llfhecap'or cover-plate 2b is arranged to screw upon the threadedcircumference of the shell ot chamber 9, and to clamp the diaphragm 3between said parts. Cap or plate 2b is provided with a projecting' neckor nipple 2C, -enteriorly threaded to receive a stop collar or nut 28adjustable on the neck 2, and held against turning by a lock-nut 29.Leak tube 6 is provided with a collar 80, which on the upward or inwardmovement of diaphragm 3 is arrested by the end of the neck 2c, and onthe reverse movement is arrested by the adjustable collar or nut 26, Byvarying the adjllstment of the collar 28 the range of movement ot theleak tube may be varied as desired..

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so that when the valve-pad or closure 33 and the leak tube 6 areslightly separated,

chamber 9 may exhaust to the atmosphere through said ports 34. The lowerend of the tube 24a carries a cap 35 containing within the tube anupward tubular extension 36,

within which is, placed a sliding plug 37 which rests uponthe upper endofa supporting and adjusting screw or spindle 38.

The tubular extension 36 of plate 35 isclosed by a screw-threaded capbetween which and the plug 37 is `interposed aspring 40. The A purposeof this arrangement is to provide av ,A

yielding support' for the tube 24, which I shall give way` in theeventof abnormal exf stressing of the parts of the mechanism, the` springbeing, however, normally inert and maintaining the base or` lower cap'at a pansion of said tube, yand thus prevent overi'iXed level vorelevation. The initial adjustment of the 'spindle 38 land consequentlyof the tube 24a is made by screwing the same up or down in its seat inthe frame l, and to the end that this adjustment may be made withnicety. Vand with reference to predetermined normal temperature, thespindle. is provided-4 withjaJ radial arm 41 having an upturned endorpointer which moves over a scale 42 j .concentric with the spindle.

" Chamber 9 .communicates by' a suitable ",-port 18a`wit-h a pipe 23which'connects with the diaphragm-motor 43- of a valve 44 indicatediii-Fig. 4, or with other device to be supplied with or actuated bylfluid pressure. In this form of the apparatus, as here illus-- trated,the'diaphragms 4 and 5 and attendant-parts are omitted. They may,however,

be employed as in Fig. 1, the illustration being designed merely toshowV the adapta.- bility of the adjustable stop to the leak tube, asapplied to that type of thermostat or control mechanism, comprisingavrestric'tedinlet port, a vent port thermostatically com" trolled, andadiaphragm-operated valve or damper.` In other Words, this ligure illus?l.trates a form ofthermostat which does not employ secondary controlmechanism, such' being within the'purvie'w of the pre'sent invention.

In Fig. 5 I -have shown a modification of the structure last described,in which the parts are substantially reversed. The inlet pipe 17 is hereconnected with a port 19in the base of the frame, controlled as beforeThe cavity l32 communicates with the atmosphere by aport or ports 34.

to the bracket 45.

this way by a needle valve or conical screw 2O inserted through anopening sealed by a screw plug 21, the pipe 23 communicating with thebase vof the tube 24h by a suitable port. The upper end of the tube 24bcarries a cap 31a which takes substantially the form and construction ofcap 2h of Fig. 3, having the neckor extension 2c upon which is threadeda nut or stop collar 28, Ibetween which and the end of extension v2cplays a collar 30n carried by a leak tube G, which in turn slidesthrough the extension 2c and is supported and actuated by a diaphragm 3subject to the pressure fluid entering through pipe 17. A spring 8serves to move the diaphragm and leak tube downward or inward when Vthetube 24b is vented to the atmosphere.

The-relief device in Fig. 5 is applied to the sealing member of the leaktube 6, which mem-ber is in the form of a sliding plug 37 movable in atubular housing 36u externally threaded and screwed into acorrespondigly tapped bracket 45 of main frame 1".

The housing 36a carries at its top a circular enlargement, thecircumference of which is ,graduated to form a scale which is readin'connection 'with an indicator 411* secured The housing 3G is formedwith an internal shoulder which limits the descent of the sliding plug37, which plug is pressed to said shoulder or seat by a spring 40 heldin place within the housing by a cap-screw 39. The upper end of the leaktube 6 enters a cavity 32 formed in vthe lower end of housing 36a, andprovided with a vent or vents 34, the same as in Fig. Collar 30a is inthe form of a nut screwed upon ,the threaded exterior of leak tube 6,

- and may hence be adjusted as desired.

Similarly, 'stop collar 28may be adjusted relatively to said nut and toneck 2. In the limits of movement of the leak tube 6 may be determined.

In Fig. 6 I employ the same mounting for Vthe tube 24c as is employedfor the tube 24" of 5, and 'the` inlet and outlet ports are to allintents and purposes the same.

The leak port is, however, formed in the lower bracket or tube support'of the frame le, as indicated by the numeral 46, said port terminatingat the under side of the bracket `in a conical seat 47 for a valve 4plug48 formedv on the lowerl end of-a stem 49 which extends upward axiallyvinto and through j the major portion of tube %c.

The stein 49 is madeV in two parts connected by a screw-threaded joint50, which vpermits elongation or contraction of 'the stem by screwingsaid partstogether or artially 'unscrewing one from the other. he uppermember of the stem 49 terminates in a head or enlargement 51, whichrests upon a spring 52 contained within a housing 53, screwed orotherwise made fast to the lower lll l ao

end of a stem 54 which is centrally clamped tothe diaphragm 3. Theperiphery of diaphragm lis clamped between the endgof tube 24C and acapl", .aspring 8 being in terposed between said cap and a clamping`disk or collar vof said diaphragm carried by stem 54. `This stem 54plays freely through a neck formed upon the cap 31", and is pro-` videdwith a` collar 54a which as the. diaphragm moves, plays Vbetween .theneck 2 anda stop-nut or collar 28 threaded upon said neck. The upperextremityl of stem54 is screw threaded and provided with a' stop nut 55.rl`he valve plug 48hassubstantiallyf` the i'orm vof a wood screw-head,Land `:is

nicked. to receive a screwdrivers".oriother` turning implement wherebythe two parts... of stern 49 may.` be screwed together, or un screwed toa sufficient extent to give proper adjustment of `the length `of the rodas a whole.

abnormaly elongation 4 of tube '24, and the nut 55, collar or nut 28,and collarftform the limitingvk stops whichdeterminel, therange otmovement of thefpartsn` and .they

consequent limits of temperature withinor therinostatic element is to,be subjected.' In

this the vframe 1i consists yof a Icasting `tapped to receive at oneside the pressure duid supply pipe 17, and at the otherside y. thepressure delivery pipe 23, Athe casting i' is being preferably formed`.with a threaded` neck`56 whereby it may be screwed into a wall voitthe tank or receptacle. Elldindicates ,the tubular thermostatic element,having a. high co-efiicient ot expansion, here f-shownhas screwed. intothe neck 56 yoi* frame or caste` ing lf in position to extendintoiandgbe con tainedwhollywithiny the tanker chamber.V Passing.axially through the tube. `Qlldfis a.

smaller tube 57, the lower end of whichis provided with a conical valvemember 58 which maybe screwed uponthe lower end 4 ci' tube 57. 4`Valve58 seats against the under side ofthe inwardly turned flange. of

an annular collar 59 screwed into the lower endof tube 2a?, land inturnclosed 'at its y lower end by a screw plug orv cap 60." Said tube '57slides throughan .openmgpin the casting 1f, and at itsuppere'nd isenlarged to receive the l`head or flange of an eXtension member 57a,theupper portion of which is eXteriorly screw threaded.` p y u rllheenlarged upper end of tube` 57 `1s screwed into'or otherwise made fastto .a central hub or boss 61 of a` diaphragm `3,

Underv this,4 arrangement the spring4 52., constitutes a reliefdevice'to guardagainst over-stressing of the lparts in' the .eventi of vper'aturathe parts `,will `standin the which is clamped to the upper endof casting or body l." by a clamping ring 62 formed or furnished with.abracket 63` which over#` hangs the diaphragm, and through which playsthe `:threaded `upperfend of extension 57u of tube 57. Encirclingextension 57 and bear-ingrat its lowerend upon the upper side ofthe`iiange thereof, isa spring.

.64, `the upper; end of .which bears against the under side. of bossA 61of diaphragm 3.

The olliceof spring 64e is to maintain the, langedlower end ofextension57 normally vin contact with thetube 57, and to cause the two sectionsofthetube to move as one,

ordinarily, but to yield in the event that the tubular member 24d ofthethermostat lengthens to such an extent `as would `lotherwisejresultin`over?stressing anypart of the structure. v

y Thescasting 1Vf iswformed witha `circular space orchamber. 9a, ofwhich diaphragm 3 forms ato p p p 'ply pipe 1` communicates by a port19,`con` Atrolledas `to capacity byl a needle valve or cone-pointedyscrew f2O, .inserted through an opening. sealed bya screw 21. Adelivery pipe"23.conne`cts `the chamber "9lwith the damper motororotherdevice to be loper-` -ated, as shown `and explained `inl*connectionwithFigs. land/lf. Bearin 'upontheup#A per?. side `of theboss 61 oi"iaphragm 3" is or closure, and with which supaspring 8, which isrelatively light or weak 'as compared with spring 64. Its oice is to"flex-l the` diaphragm `3 y downward, `or insl v ward when not opposedby asuperior force. 65 indicates a nut screwed 4 upon the threaded endof extension 57",` below`the overhanging upper end of bracket 63. Thisnut constitutes an adjustablestop to limit and `determine the`movementof leak tube 57. Anindicator arm or pointer screwed uponV the`upper end `of` extension '57* "and resting upon the bracket `63,serves, when*` swung in. one Vor the other' direction, to Araise` y'orlowerthe' leak tube`15.7, 57a, and to ad# just itsyalve 58 relativelyto then-seat in; collar 59. The leak ports of extension 57B areshown`opening laterally from its eenV tral bore `or passage, to avold undulywea-lb ening` the` threaded portion ofsuchhextension, but this isnotessentlal'. Communication between `thefinterior of' thermostatic' member245'? and chamber 9; is aiiorded b portsformed .in casting 12,01' by aloose t oftube `57l therein.` i v y y v The device constructed as aboveexplained and placed in communication -with a source of Huid y underpressure, operates as follows:

` v.Assuming thatthe` contents `of thetank `or chamber, 66 "be ofsufliciently `high teinpoSltions indicated in Fi 7, "with, valve 58 vseatedand leak tube` 5 outof communication with chamber 9.1 So long asthe teinj tube 5 7 Escape valve seat into'contact with valve 58, therebyperature is maintained and. valve 58 remains seated,

pressure will build upin chamber 9, diaphragm 3 will be maintained inits upwardly flexed position, and valve 58 will be held to its seat. If,however, the temperature falls, thetubular member 24d of the thermostatwill contract or shorten, thus -the tank or chamber 66, will causethetubular member 24d to lengthen vand to carry` the sealin theleak'port, causing the' pressure l shutting olf the heat supply.

to bui d up in chamber 9 and in pipe 23. and the connected' valve ordamper-motor, and Theaction is rendered promptby upward iexing ofdiaphragm `3 through accumulating. pressure beneath it in chamber 9,yand consequent-lifting of leak tube 57 and movement of valve 58 towardthe advancing valve seat. The extent of this movement is determined andcontrolled by-- the nut or adjustable Sap 65. n Fig. 8 `I haveillustrated a structure identical wlth that of Fig.- 1 except -that theleak port valve 25 is carried by a resilient bar 24 which tends 'to movetoward and to close the leak tube 6, but which is controlled as to itsposition by a block 67 of Wood or other material which expands in a'moist atmosphere and contracts in a dry atmosphere. Under thisarrangement the leak port will be sealed and pressure fluid will besupplied to a motor which opens the valve controlling delivery ofmoisture to Athe surrounding atmosphere. When the proper degree ofhumidity is restored the block 67, expanding, will force. back the bar24', unseat valve 25', vent the valve motor,

and shut 'off the supply of moisture. Ad-

justing devices for bar 24 may be provided,

as in Fig. 4 of Patent No. 1,162,170.

As explained in 'said Patent No. 1,162,170, the distinctive feature ofthe type of instrument to which my present invention'is applied is thatit provides a quick acting vent valve, which moves so promptly from fullopen to full closed position as to obviate the necessity of a quickthrow device between the control diaphragm or primary motor and thecontrol mechanism. This not only avoids the complication incident tosuch a quick throw device, but, provides a valve which is much moresensitive than those of earlier forms, and which has no neutralposition. In other words, the essential characteristic of this type isthe quick-acting thermostatic vent valve, in combination with a' primarypressure motor` such as the diaphragm 4: of Fig. 1. This primary motormay, as shown, actuate a control valve to regulate the operation of asecondary iuid pressure motor, or it may actuate any other type ofcontrol mechanism, adapted to control the operation of any othercorresponding type of secondary motor, such devices being'knownequivalents in the art.

The primary motor may be used to operate a wide range of devices and isapplied to such use. It is also evident that the vent valvemay takedifferent forms, so long as .the essential feature is retained, or solong as the valve comprises co-acting elements, one of which is movableby a thermostatic, hygrostatic, or other responsive element aflfected bychanges of atmospheric condition,

and the other of which is moved in a closing direction by `an initialincrease of pressure 1n the chamber 9, and in an opening rection by. aninitial decrease of pressure 1n suchv chamber.

The present invention consists in the provision of an adjustable stop orstops to limit and determine the range of movement of thepressure-actuated element of such valve, whereby the rangeof temperaturevariation within which, or the limits between which,

said valve shall act, may be varied and determined, but a prompt openingat one limit of said range and a quick closing at the other extreme,shall be effected.

The thermostat here described in each and all the embodimentsillustrated, and in other variants thereof that willreadilysugautomatically supplies an alternating high and low temperature whichis desirable in Certain manufacturing` and laboratory processes, incertain machines, and in other equipment where it is desirable to havethese alternations in temperature made automatically and repeatedly orperiodically with machine-like precision in contrast `with all formerthermostats or thermostatic controllers of the leak port typeof which Iam aware, such prior devices being specially designed and intended tomaintain the temperature constant or as nearly constant as ispracticable.

'In the claims I make use of the term abutment to include such devicesas pistons, diaphragms, etc., all of which are well known equivalents inthe art.

rl`he term responsive element in the claims includes thermostatic,hygrostatic, and other elements subject to a change of `gest themselvesto those skilled in theart,

form or dimension in response to changes in atmospheric condition.

Having thus described my invention what l claim is i 1. rlhe combinationof a fluid pressurel motor; a source of fluid pressure in communicationtherewith; a leak port member for said motor, adapted `to be moved bypressure within said motor; a `closure for said leak port member locatedin line therewith, having automatic actuating `means responsive tochanges in atmosphericcondition, said leak port member bein' movabletoward said closure upon a rise o pressure in said motor, j effected;and an adjustable stop for the movable leak port member, whereby therange within which opening and closing of the leak port is effected maybe varied. l

2. rlhe combination of a fluid lpressure motor; a source of fluidpressure communicating therewith; a leak: port member for said motormovable under variations `of y pressure in said motor; a closure forsaid leak portl member located in line therewith, having automatic meansresponsive to changes in atmospheric condition, said leak port memberbeing adapted to move away from said closure upon a fall of pressure insaid motor to edect a quick venting; and` an. adjustable stop to limitand `determine the movement of said leak port member, and therebyl todetermine the limits of` atmosv pheric change at which opening' andclosing;r of the leak port shall respectively occur.-

3. The combination `of a control mechanism for a motor; a fluid pressureactuated abutment adapted to operate said control `mechanism; a sourceof fluid pressure in ll'll.

communication therewith; a vent valve mechanism responsive vtov changesin at-n mospheric condition, adapted to vent fluidl pressure actin onsaid abutment; a pressure-actuated evice subject to the fluid pressureacting on said',aloutment,` and adapted to co-act with the vent valvemechanism to close the same upon an initial increase of fluid pressureand to open thesame upon an initial decrease of pressure; andanadjustable stop to `limit and determine the range of movement of saidvent valve mechanism.` j A il. lhe combination of a control mechi anismfor a motor; a Huid-actuated abutment adapted to-operate said contr'olmeehanism; a source of fluid pressure communi-l eating therewith; aventvalve mechanism responsive to changes in atmospheric condition adaptedto vent fluid ressure acting on said abutment; a diap ragm springpressedin one direction and subject to the fluid pressure acting on saidabutment in the reverse direction, adapted upon an initial increase ofsuib pressure to close said vent whereby quick sealing is adapted tooperatesaid control mechanism;

`a source of fluidpressure in communication therewith; a movable valve.memberhaving a port adapted to; vent pressure from said abutment asecond movable valve member' adapted. to co-act with the first movablevalve `member -to control the vent port therein; a responsiveelementoperativelyl con-` nected to move one valve member in response tovariations inf atmospheric condition; a

pressure-actuated device-subject to the pres. sure acting on saidabutment and adapted to co-actuwiththe other valve member to move thesame ina closing direction upon an initial increase of such pressure andin an opening direction upon an initial decrease in `such pressure; andan adjustable stop serving to` limit and determine the movement of` said.pressure-actuated device.

6. The` combination of` a control mechanism adapted to control theoperation of a motor; a luid-pressure-actuated abutment adapted tooperate said control mechanism;

a sourceof fluid pressure in communication therewith; a'movable valvemember having a Iport adapted to vent pressure from said abutment; aseeondmovable valve member.

adapted to co-act with the first movable valve member to control thevent port therein; aresponsive element operatively conioo nected to moveone valve member in respouse to variations in atmospheric condition;avdiaphragm spring-pressed in one direction and subject to the pressureacting on said abutment in the opposite direction, adapted to co-actwith the other valve member to move the same in a `closing directionupon an initial increase in such pressure and in an openingdirectionfupon an initial decrease therein; and an adjustable .stop tollimit and determinethe range of movement of said port-containing valvemember.

'l'. The combination with a control mechanism including` a pressurechamber and a source of Huid pressure communicating therewith, Vot' avalve member 'having a sealving' face; a responsive element` adapted toi move said valvenember; a vent tube adaptedto vent pressure from saidchamber and mounted to move toward and from said sealing face to closeand open said tube; an abutment subject to pressure in said chamber andconnected to said vent tube to move the same toward said sealing face:resilient means opposing such movement; and an adjustable stop servingto limitand determine the movement of said vent tube.`

ica

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8. The combination with a control mechanisln including a pressurechamber and a source of fluid pressure communicating therewith, of avalve member having a sealing face; a responsive element ,adapted tomove said valve member; a vent tube adapted to vent pressure from saidchamber and mounted to have movement tow ard and from said sealing faceto close and open said tube; a resilient diaphragm connected to saidtube, subject to the pressure in said chamber, and adapted to urge saidt-ube toward said sealing face in opposition to the resilience of saiddiaphragm; and an adjustable-stop to limit and determine the movementsof said vent tube.

9. The combination with a control mechanism including a pressure'chamber and a source of Huid pressure in communication therewith, of amovable valve having a sealing face; a responsive element adapted tomove said valve; avent tube adapted to vent pressure from said chamberand mounted to have a movement toward and Jfrom said j sealing face; amechanism subj ect to pressure in said chamber, connected to said venttube,

and adapted to move the latter into sealing engagement with said`sealing face upon an initial rise of pressure in .said chamber and outof such engagement upon an initial fall of such pressure; and anadjustable stop serving to limit and determine the extent of movement ofsaid vent tube.

10. A vent valveI for a pressure motor control device, comprising aventv tube mounted to permit longitudinal movement; a -re- .sponsiveelement having a sealing face movable under changes of atmosphericcondition into and out of sealing relation with the end 'of said tube;an abutment connected to said tube and subject to the pressure to beventl ed, urging said tube toward said sealing face; resilient meansacting in opposition to the pressure on said abutment; and an adjustablestop serving to limit and determine the extent of movement of said venttube.

1-1. A vent valve for a pressure motor control device, comprisingr avent tube mounted to permit longitudinal movement; avre- 50 sponsiveelement having a sealing face movable-under changes of atmosphericcondition into and out of sealing relation with the end of said tube; adiaphragm connected to said tube, spring-pressed in one direction andsubject to the opposing pressure to be vented, acting to move said tubetoward said sealing face; and an adjustable stop serving to limit anddetermine-the extent of movement of the vent tube.

12. A vent valve for a pressure motor control device, comprising a valvemember having a vent port; a second valve member l:o-acting with the rstto control said vent n port; a responsive element adapted to move onevalve member in response to variations in atmospheric condition; apressure actuated device subject to the pressure to be vented andadapted upon a rise ot' such pressure to move the other valve membertoward said closed position and upon fall of such pressure, toward openposition; and an adjustable stop to limit the movements of said valvemember.

13. In a control device, a valve adapted alternately to supply andexhaust fluid pressure to and from a secondary device; means urging saidvalve toward exhaust position; a valve-actuating motor adaptedl underpressure to force said valve from exhaust to supply position; aresponsive element having a sealin face adapted. to move in accordancewit i variations of atmospheric condition; a vent tube adapted to ventpressure from said motor andI to move into and out of sealing relationwith said sealing face;

van adjustable stop to limit and determine the movement of said venttube; and a pressure-actuated device subject to pressure in said motor,connected to said vent tube, and adapted to move the latter toward saidsealing face upon an increase of such pressure and away from saidsealing face upon a decrease of such pressure.

. 14. In a control device, a valve adapted alternately to supply andexhaust fluid pressure to` a secondary device, meansv urging said valvetoward exhaust position; a valveactuating motor adapted under pressureto force said valve from exhaust to supply position; a responsiveelement having a sealing face adapted to move in accordance withvariations of atmospheric condition; a vent tube adapted to ventpressure from said motor and to move into and out of sealing relationwith said sealing face; a springlpressed diaphragm subject to opposingpressure in said motor, connected to said vent tube, and adapted to movethe latter toward said sealing face upon an increase 'of pressure andaway from said sealing face upon a decrease of pressure; and anadjustable sto to limit and determine the movement of sai vent tube.

15. A vent valve for a-iuid'pressure control device including a movablemember having a vent port; an adjustable stop serving to limit anddetermine the range of movement of said member; a valve member co-actingtherewith to control said port; a responsive element adapted to movesaid valve member through variations in atmospheric conditions; and apressure-actuated device subject to the pressure to be Vented andadapted upon a rise of pressure to move the vent member toward itssealing valve. 16. An automatic control device of the leak port member;a sealing device for said l0 to determine the limits of movement of theleak port element, whereby the extent of such movement may be initiallydetermined and the sealing device be caused to seal and unseal the leakport at'the limits of predetermined ra-nge of variation in atmosphericconditions.

In testimony whereof I have signed Vmy name to this specification.

CARL F. JOHNSON.

